There are two artificial sweeteners in this product: sucralose, and acesulfame potassium (also known as Ace-K). The purpose of using two sweeteners is to get a better sugar-like taste profile than with a single sweetener alone.
You can read the relevant Wikipedia articles on these substances, but suffice it to say that neither one is really all that good to consume frequently, even if they are GRAS (generally recognized as safe) or have agency/governmental approval. We can talk about extensive LD50 animal studies, or PK studies in humans, but at the end of the day, nothing is completely safe--toxicity is a measure of exposure over time, and an excess of anything is bad no matter what it is you're putting in your body.
In light of this, the most important thing if you want to use supplements in a healthy way is to do it in moderation. As difficult as it might be to obtain your nutrition through whole foods, supplementation is precisely that--supplementing your normal diet, not substituting for it. It's not about increasing convenience by allowing you to cut back on eating as much of your dietary needs as you possibly can.